While I'm also not aware of a shrinking game, there are more than a few[1] growing games. Some aspects of the mechanic are the same - "what was dangerous before is not a problem now and vice versa"; it's just the plot that changes.
So: in a shrinking game a small enemy will become a large threat and a narrow passage will become a large escape route - and in a growing game a large enemy will turn into a small threat and a previously large passage will become inaccessible.
There was a game called Specter Spelunker Shrinks that required arbitrary shrinking and growing. It's more of a prototype than a full game, but I could imagine this exact mechanic working in a more fleshed out setting.
A cool thing about the game is that time also scales with size. So the challenge provided by moving objects also scales with the character's size (sometimes beneficially, sometimes not).
(Ostensibly, in a growing game you get bigger as the game progresses and vice versa for a shrinking game; this lets one play with perspective to make things bigger or smaller as needed.)
Reminds me of a proposal I've seen floating around for a Metroidvania game where you lose abilities as you progress (never gaining them back.)
IIRC the idea is that it would still be a game with progressive exploration (if not necessarily Metroidvania-style exploration), as terrain-navigation-gated area design would be combined with more-mainstream keys-and-locks area design — so while you're losing your abilities that allow you to "sneak in through the back door" of areas, you're gaining key items/flipping switches/making friends that enable you to "come in through the front door" instead.
Also, as with a "shrinking game", you'd see things you're currently "too powerful" to enter and need to come back when you're "weaker." In this case, because some abilities you start with would be too powerful — trading that power off for having too little precision/finesse — and so would be preventing you from entering some areas because every time you try to do so, the ability kicks in and pushes you past the gap you were trying to fit into (or whatever.) It's only once you lose the ability that you gain the precision required to aim for the gap.
> Metroidvania game where you lose abilities as you progress
This is brilliant. It solves the inherent tension of metroidvanias wanting both ever-increasing power and ever-increasing challenge. Rather than unlocking new areas, each time you lose abilities, it changes your relationship to existing areas. But the knowledge you gain — room layouts, enemy placement, hazards, short cuts, etc — becomes way more helpful when you can't just fly (perhaps literally) across the map.
Seems very unlikely to work. Most metroidvania mechanics are not "useful", they're just "required" like barrier breakers or hazard resistances. Players don't actually care about having the latter. Taking away the ability open orange doors isn't really different from introducing new purple doors that you can't open.
The tech that is useful, like dashes and double jumps, is really nice to have but not especially interesting to lose imo. If you "need" the dash then it's just a key. If you don't need the dash then losing it is just less satisfying movement.
Baba is You does this by giving you a bunch of tools to solve a level, then taking away one of them (or neutering it) and challenging you to solve it again as an Extra.
It's fun because it makes you realize that you already had the power for a more a different solution, but didn't notice.
This idea is really interesting to me but it seems like it would be hard to capture a similar kind of fun as progressing in a traditional metroidvania. That there is a trade-off between player movement abilities and map shortcuts is interesting enough to warrant a purchase (big fan of the genre, personally) but "100%" saves and the like could possibly be un-fun to make.
Although, I'm already imagining a sequence where you trade away your last movement ability and walk down some long-ish path to a place where you get all or most of them back (or different ones!). That could be fun and rewarding but it would definitely have to be done right.
My boss and a long time good friend developed one[1] with his previous indie studio. Originally VR but playable with mouse and keyboard too, player can shrink both themselves and their enemies.
(Not trying to advertise for sales as the company went under years ago)
> I haven’t seen anyone do a shrinking game.
While I'm also not aware of a shrinking game, there are more than a few[1] growing games. Some aspects of the mechanic are the same - "what was dangerous before is not a problem now and vice versa"; it's just the plot that changes.
So: in a shrinking game a small enemy will become a large threat and a narrow passage will become a large escape route - and in a growing game a large enemy will turn into a small threat and a previously large passage will become inaccessible.
[1]: E.g. https://en.wikipedia.org/wiki/Katamari_Damacy